Assessment of the effects of switching oral bisphosphonates to denosumab or daily teriparatide in patients with rheumatoid arthritis

Kosuke Ebina, Makoto Hirao, Jun Hashimoto, Keisuke Hagihara, Masafumi Kashii, Kazuma Kitaguchi, Hozo Matsuoka, Toru Iwahashi, Ryota Chijimatsu, Hideki Yoshikawa

The aim of this observational, non-randomized study was to clarify the unknown effects of switching oral bisphosphonates (BPs) to denosumab (DMAb) or daily teriparatide (TPTD) in patients with rheumatoid arthritis (RA). The characteristics of the 194 female patients included in the study were 183 postmenopausal, age 65.9 years, lumbar spine (LS) T score -1.8, femoral neck (FN) T score -2.3, dose and rate of taking oral prednisolone (3.6 mg/day) 75.8%, and prior BP treatment duration 40.0 months. The patients were allocated to (1) the BP-continue group (n = 80), (2) the switch-to-DMAb group (n = 74), or (3) the switch-to-TPTD group (n = 40). After 18 months, the increase in bone mineral density (BMD) was significantly greater in the switch-to-DMAb group than in the BP-continue group (LS 5.2 vs 2.3%, P < 0.01; FN 3.8 vs 0.0%, P < 0.01) and in the switch-to-TPTD group than in the BP-continue group (LS 9.0 vs 2.3%, P < 0.001; FN 4.9 vs 0.0%, P < 0.01). Moreover, the switch-to-TPTD group showed a higher LS BMD (P < 0.05) and trabecular bone score (TBS) (2.1 vs -0.7%; P < 0.05) increase than the switch-to-DMAb group. Clinical fracture incidence during this period was 8.8% in the BP-continue group, 4.1% in the switch-to-DMAb group, and 2.5% in the switch-to-TPTD group. Both the switch-to-DMAb group and the switch-to-TPTD group showed significant increases in LS and FN BMD, and the switch-to-TPTD group showed a higher increase in TBS compared to the BP-continue group at 18 months. Switching BPs to DMAb or TPTD in female RA may provide some useful osteoporosis treatment options.